War Horse has been a sensation. The tale of Joey, a horse who serves in the First World War, it was originally a children's novel, then a sell-out stage play before eventually becoming a blockbuster movie. It's a remarkable success for its author Michael Morpurgo. He's an award-winning former children's laureate with more than 100 books to his name. But when he's asked, Michael says that something altogether different is his 'greatest story'. It's not a novel or a children's book; it's the charity Farms for City Children which he set up with his wife Clare, in 1976.

The idea was a simple one, to give urban youngsters a chance to live and work on a real farm for a week as a way of reconnecting the children to food and farming. The Morpurgos knew that it wasn't enough just to have children stay on their West Country farm and watch what happens; they had to get their hands dirty by carrying out essential tasks like digging, planting, feeding livestock and yes, even mucking out. It's what Michael calls "learning through doing".

Now, 40 years on, Farms for City Children goes from strength to strength. The charity welcomes 3,000 schoolchildren every year to its three farms: the Morpurgo's original mixed dairy, beef and sheep farm in Devon; a 700- year-old sheep farm in Pembrokeshire called Lower Treginnins; and Wick Court on the banks of the River Seven in rural Gloucestershire.

Little Farm in the Big Smoke

While farms for education are nothing new, there seems to be a growing demand for them. It's not just happening in rural locations. The alternative to taking urban children to farms in the countryside is to bring agriculture to them. The first city farm in the UK was created in Kentish Town, London 1972. It's hard to imagine a more built up environment. The farm sits next to two railway lines, overlooked by tower blocks. Yet the organisers defied the odds and their critics to make a home for cattle, sheep, goats and more, and establish a riding stable.

It even attracted attention of the Prince of Wales. During a visit 1979, Prince Charles made a Jubilee Trust film about the initiative and was plainly impressed: "The city farm sounds like a contradiction in terms and perhaps that's what makes it such a worthwhile idea... children who don't often get a chance to see a green field have had the farmyard delivered to their doorstep with obvious appreciation".

It wasn't long before other groups were inspired to set up their own urban farms and now there are well over 100 in places such as Edinburgh, Liverpool and Bristol, with more on the way. Meanwhile, the benefits of a new type of educational agriculture are beginning to be widely recognised. Care Farms do an amazing job providing help, therapy or social skills to a range of people in need. Their visitors include those with mental health problems, recovering drug or alcohol addicts, and children with autism or learning difficulties. It all proves that there's an importance to farming that goes a way beyond simply providing food and fuel.